TRAUMATIC BRAIN INJURY PATIENT INFORMATION This resource, developed by neurosurgeons, provides patients and their families trustworthy information on neurosurgical conditions and treatments. For more patient resources from the American Association of Neurological Surgeons (AANS), visit www.aans.org/Patients. Traumatic Brain Injury | American Association of Neurological Surgeons A traumatic brain injury (TBI) is defined as a blow to the head or a penetrating head injury that disrupts the normal function of the brain. TBI can result when the head suddenly and violently hits an object or when an object pierces the skull and enters brain tissue. Symptoms of a TBI can be mild, moderate or severe, depending on the extent of damage to the brain. Mild cases may result in a brief change in mental state or consciousness, while severe cases may result in extended periods of unconsciousness, coma or even death. Prevalence About 1.7 million cases of TBI occur in the U.S. every year. Approximately 5.3 million people live with a disability caused by TBI in the U.S. alone. Incidence and Demographics ● Annual direct and indirect TBI costs are estimated at $48-56 billion. ● There are about 235,000 hospitalizations for TBI every year, which is more than 20 times the number of hospitalizations for spinal cord injury. ● Among children ages 14 and younger, TBI accounts for an estimated 2,685 deaths, 37,000 hospitalizations and 435,000 emergency room visits. ● Every year, 80,000-90,000 people experience the onset of long-term or lifelong disabilities associated with TBI. ● Males represent 78.8 percent of all reported TBI accidents and females represent 21.2 percent. ● National statistics estimate between 50-70 percent of TBI accidents are the result of a motor vehicle crash. ● Sports and recreational activities contribute to about 21 percent of all TBIs among American children and adolescents. ● The mortality rate for TBI is 30 per 100,000, or an estimated 50,000 deaths in the U.S. annually. Of those who die, 50 percent do so within the first two hours of their injury. ● Deaths from head injuries account for 34 percent of all traumatic deaths. Beginning at age 30, the mortality risk after head injury begins to increase. Persons age 60 and older have the highest death rate after TBI, primarily because of falls, which have a rising incidence in this age group. Sources: Centers for Disease Control and Prevention (CDC), Traumatic Brain Injury (TBI): Incidence and Distribution, 2004. Traumatic Brain Injury Model System, University of Alabama at Birmingham, Introduction to Brain Injury – Facts and Stats, February, 2000 TBI Symptoms Symptoms vary greatly depending on the severity of the head injury, but may include any of the following: ● Vomiting ● Lethargy ● Headache ● Confusion ● Paralysis ● Coma ● Loss of consciousness ● Dilated pupils ● Vision changes (blurred vision or seeing double, not able to tolerate bright light, loss of eye movement, blindness) ● Cerebrospinal fluid (CSF) (which may be clear or blood-tinged) coming out of the ears or nose ● Dizziness and balance problems ● Breathing problems ● Slow pulse ● Slow breathing rate, with an increase in blood pressure ● Ringing in the ears or changes in hearing ● Cognitive difficulties ● Inappropriate emotional responses ● Speech difficulties (slurred speech, inability to understand and/or articulate words) ● Difficulty swallowing ● Body numbness or tingling ● Droopy eyelid or facial weakness ● Loss of bowel control or bladder control If a TBI is suspected, call 911 immediately or take the person to an emergency room. Surgical Lesions When discussing TBI, the term "mass lesion" is often used. This refers to an area of localized injury that may cause pressure within the brain. The most common mass lesions related to TBI are hematomas and contusions. A hematoma is a blood clot within the brain or on its surface. Hematomas may occur anywhere within the brain. An epidural hematoma is a collection of blood between the dura mater (the protective covering of the brain) and the inside of the skull. A subdural hematoma is a collection of blood between the dura mater and the arachnoid layer, which sits directly on the surface of the brain. www.aans.org/Patients Page 1 of 6 Traumatic Brain Injury | American Association of Neurological Surgeons A cerebral contusion is bruising of brain tissue. When examined under a microscope, cerebral contusions are comparable to bruises in other parts of the body. They consist of areas of injured or swollen brain mixed with blood that has leaked out of arteries, veins or capillaries. Contusions are seen most commonly at the base of the front parts of the brain, but they may occur anywhere. An intracerebral hemorrhage (ICH) describes bleeding within the brain tissue, which may be related to other brain injuries, especially contusions. The size and location of the hemorrhage helps determine whether it can be removed surgically. Subarachnoid hemorrhage (SAH) is caused by bleeding into the subarachnoid space. It appears as diffuse blood spread thinly over the surface of the brain and is seen commonly after TBI. Most cases of SAH associated with head trauma are mild. Hydrocephalus may result from severe traumatic SAH. Diffuse Injuries TBI can produce microscopic changes that cannot be seen on CT scans that are scattered throughout the brain. This category of injuries is called diffuse brain injury, which may occur with or without an associated mass lesion. Diffuse axonal injury refers to impaired function and gradual loss of some axons, which are the long extensions of a nerve cell that enable such cells to communicate with each other even if they are located in parts of the brain that are far apart. If enough axons are injured in this way, then the ability of nerve cells to communicate with each other and to integrate their function may be lost or greatly impaired, possibly leaving a patient with severe disabilities. Another type of diffuse injury is ischemia, or insufficient blood supply to certain parts of the brain. It has been shown that a decrease in blood supply to very low levels may occur commonly in a significant number of TBI patients. This is crucial because a brain that has just undergone a traumatic injury is especially sensitive to even slight reductions in blood flow. Changes in blood pressure during the first few days after head injury can also have an adverse effect. Skull Fractures No treatment is required for most linear skull fractures, which are simple breaks or "cracks" in the skull. Of greater concern is the possibility that forces strong enough to cause a skull fracture may also have caused some damage to the underlying brain. Fractures of the base of the skull are problematic if they cause injury to nerves, arteries or other structures. If a fracture extends into the sinuses, there may be leakage of cerebrospinal fluid (CSF) from the nose or ears. Most leaks will stop spontaneously. Sometimes, however, it may be necessary to insert a lumbar drain, which is a long, thin, flexible tube that is inserted into the CSF space in the spine of the lower back. This provides an alternate route for CSF drainage so that the dural tear that is responsible for the CSF leak in the base of the skull has time to seal. Depressed skull fractures are those in which part of the bone presses on or into the brain. These may require surgical treatment. The damage caused by depressed skull fractures depends upon the region of the brain in which they are located and also upon the possible coexistence of any associated diffuse brain injury. Diagnosis Like all trauma patients, persons with TBI need to undergo a systematic yet rapid evaluation in the emergency room. Cardiac and pulmonary function is assessed first. Next, a quick examination of the entire body is performed, followed by a complete neurological examination. The neurological examination includes an assessment utilizing the Glasgow Coma Scale (GCS). In addition to the GCS, the ability of the pupils to become smaller in bright light is also tested. In patients with large mass lesions or with high intracranial pressure (ICP), one or both pupils may be very wide or "blown". The presence of a wide or dilated pupil on only one side suggests that a large mass lesion may be present on the same side as the dilated pupil. Brainstem reflexes including gag and corneal (blink) may also be tested. Radiological Tests A computed tomography scan (CT or CAT scan) is the gold standard for the radiological assessment of a TBI patient. A CT scan is easy to perform and is an excellent test for detecting the presence of blood and fractures, which are the most crucial lesions to identify in medical trauma cases. Plain x-rays of the skull are recommended by some as a way to evaluate patients with only mild neurological dysfunction. However, most centers in the U.S. have readily available CT scanning, which is a more accurate test. For this reason, the routine use of skull x-rays for TBI patients has declined. Magnetic resonance imaging (MRI) is not commonly used for acute head injury because it takes longer to perform MRI than a CT. MRI is not as practical for acute trauma because it is difficult to transport an acutely-injured patient from the emergency room to the MRI scanner. However, after a patient has been stabilized, MRI may demonstrate the existence of lesions that were not detected on the CT scan. This information is generally more useful for determining prognosis than for influencing treatment. Surgical Treatment Many patients with moderate or severe head injuries are taken directly from the emergency room to the operating room. In many cases, surgery is performed to remove a large hematoma or contusion that is significantly compressing the brain or raising the pressure within the skull.